Hi,
I manage to do this having downloaded the free "morefunc" add-in.
First you need to find the number corresponding to your fill colour, so fill
a cell (say A1) with a grey colour (middle one one the right in my pallette),
and in A2 enter =XLM.GET.CELL(63,A1)
This will return a number, 48, in this case.
Now you know the number, you can get rid of the above.
Now, in F2, enter
=IF(XLM.GET.CELL(63,A2)=48,"YES","")
If A2 has a midgrey fill, then F2 will display the word YES, otherwise it
will display nothing.
The drawback is that it doesn't update automatically, so you need to force a
recalculation (with F9, for instance), and also it won't work if the fill is
applied with conditional formatting. In that case, you need to apply the same
logic to a formula in F2 that triggered the conditional formatting in A2.
Dave